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Biomedical subjects

Y Kitamura

Publications and source records attributed to Y Kitamura.

At least 595 records · Page 33Linked to original sources
PubMed1988

Electron microscopic changes of bone marrow-derived cultured mast cells after injection into the skin of genetically mast cell-deficient W/Wv mice.

Phenotypes of bone marrow-derived cultured mast cells are different from those of connective tissue-type mast cells (CTMCs) that are found in the peritoneal cavity and the skin. When cultured mast cells of WBB6F1 - +/+ mouse origin were directly injected into the skin of genetically mast cell-deficient WBB6F1 - W/Wv mice, mast cells appeared in both the dermis and the subcutaneous tissue (beneath the panniculus carnosus). In contrast to cultured mast cells, mast cells that were observed in either the dermis or the subcutaneous tissue were stained with berberine sulfate, suggesting the content of heparin. Cultured mast cells acquired the electron microscopic features of CTMC in either the dermis or the subcutaneous tissue of WBB6F1 - W/Wv mice, but the electron density of mast-cell granules was significantly higher in the dermis than in the subcutaneous tissue. Such an electron microscopic difference was also observed after the injection of purified peritoneal mast cells of WBB6F1 - +/+ mice into the skin of WBB6F1 - W/Wv mice. From the present study, we suggest that the electron density of mast-cell granules in the skin of WBB6F1 - W/Wv mice is not dependent on the type of injected mast cells but on the anatomical sites at which the injected cells are located.

Animals↗
PubMed1988

Development of spindle-shaped cells and chondroid cells from androgen-dependent Shionogi carcinoma 115. A light and electron microscopic study.

Androgen-dependent Shionogi carcinoma 115 (SC115) is an undifferentiated medullary carcinoma consisting of compact round cells. However, when host male DS mice were castrated 2 weeks after tumor transplantation, tumors composed of compact round cells, spindle-shaped cells and chondroid cells grew 4 weeks after castration. Compact round cells with desmosomes were arranged in solid nests and exhibited immunoreactivity for keratin protein. Spindle-shaped cells had prominent rough endoplasmic reticulum, and appeared to secrete collagen. Chondroid cells had the characteristics of chondrocytes. The light and electron microscopic features were highly suggestive of a transition from compact round cells to spindle-shaped cells, and from spindle-shaped cells to chondroid cells. The histology of this tumor thus suggests that SC115 cells are able to change into chondroid cells via spindle-shaped cells.

Androgens↗
PubMed1988

Studies of Sl/Sld in equilibrium with +/+ mouse aggregation chimaeras. I. Different distribution patterns between melanocytes and mast cells in the skin.

In spite of their different origin, both melanocytes and mast cells are deficient in the skin of mutant mice of the Sl/Sld genotype. Since the neural crest and the liver of Sl/Sld embryos contain normal precursors of melanocytes and mast cells, respectively, the deficiency is attributed to a defect in tissue environment necessary for migration and/or differentiation of precursor cells. We investigated whether the tissue environment used for differentiation of melanocytes and mast cells was identical by producing aggregation chimaeras from Sl/Sld and +/+ embryos. Chimaeric mice with apparent pigmented and nonpigmented stripes were obtained. In the nonpigmented stripes of these Sl/Sld in equilibrium with +/+ chimaeras, melanocytes were not detectable in hair follicles but were detectable in the dermis. In contrast, melanocytes were detectable neither in hair follicles nor in the dermis of nonchimaeric Sl/Sld mice. Concentrations of mast cells were comparable in the pigmented and nonpigmented stripes of Sl/Sld in equilibrium with +/+ chimaeras, but the average concentration of mast cells significantly varied in the chimaeras (from 8% to 74% of the value observed in control +/+ mice). The present result suggests that mesodermal cells that support the migration and differentiation of both melanocyte precursors and mast-cell precursors mix homogeneously in the dermis and that ectodermal cells that influence the invasion of differentiating melanocytes into hair follicles make discrete patches.

Animals↗
PubMed1988

Studies of Sl/Sld in equilibrium with +/+ mouse aggregation chimaeras. II. Effect of the steel locus on spermatogenesis.

Mutant mice of Sl/Sld genotype are deficient in melanocytes, erythrocytes, mast cells and germ cells. Deficiency of melanocytes, erythrocytes and mast cells is not attributable to an intrinsic defect in their precursor cells but to a defect in the tissue environment that is necessary for migration, proliferation and/or differentiation. We investigated the mechanism of germ cell deficiency in male Sl/Sld mice by producing aggregation chimaeras from Sl/Sld and +/+ embryos. Chimaeric mice with apparent white stripes were obtained. Two of four such chimaeras were fertile and the phenotypes of resulting progenies showed that some Sl/Sld germ cells had differentiated into functioning sperms in the testis of the chimaeras. In cross sections of the testes of chimaeras, both differentiated and nondifferentiated tubules were observed. However, the proportions of type A spermatogonia to Sertoli cells in both types of tubules were comparable to the values observed in differentiated tubules of normal +/+ mice. We reconstructed the whole length of four tubules from serial sections. Differentiated and nondifferentiated segments alternated in a single tubule. The shortest differentiated segment contained about 180 Sertoli cells and the shortest nondifferentiated segment about 150 Sertoli cells. These results suggest that Sertoli cells of either Sl/Sld or +/+ genotype make discrete patches and that differentiation of type A spermatogonia does not occur in patches of Sl/Sld Sertoli cells.

Animals↗
PubMed1988

Developmental changes in the levels of substrates for cholera toxin-catalyzed and pertussis toxin-catalyzed ADP-ribosylation in rat cardiac cell membranes.

Developmental changes in the substrates for cholera toxin (CTX)- and pertussis toxin (PTX)-catalyzed ADP-ribosylation in cardiac (ventricular) cell membranes were studied in fetal (16- to 20-day), neonatal (0- to 20-day) and adult (2- to 3-month) rats. The CTX and PTX substrates were determined by the method of CTX-catalyzed and PTX-catalyzed ADP-ribosylation of the alpha-subunit of GTP-binding (G) proteins, respectively. As early as fetal day 16, three substrates (45-, 47- and 52-kDa proteins) were identified for CTX-catalyzed ADP-ribosylation and one substrate (41-kDa protein) for PTX-catalyzed ADP-ribosylation. The levels of the three CTX substrates (fmol/mg tissue) increased with development between fetal day 16 and neonatal day 16, and then they decreased to their adult levels. The level of the one PTX substrate (fmol/mg tissue) changed as follows: the substrate decreased between fetal day 16 and the day of birth, increased abruptly for 4 days neonatal and increased slowly thereafter until neonatal day 16, and then decreased to the final adult level. The PTX substrate seems to reach a nearly maximum level earlier than the CTX substrates. This information is essential for understanding the developmental changes in the transmembrane signaling system between membrane receptors and their effectors which are coupled with the stimulatory and inhibitory G proteins.

Adenosine Diphosphate Ribose↗
PubMed1988

Proliferative response of seminal vesicle cells to androgen in mice castrated neonatally and pretreated with estrogen or androgen at adulthood.

Seminal vesicle cells of neonatally castrated adult mice show poor response to androgen, compared to those of mice castrated at adulthood; effects of pretreatment with androgen or estrogen at adulthood on androgen-induced proliferation of the seminal vesicle cells were examined in neonatally castrated mice. Male mice castrated at day 0 after birth were pretreated with daily injections of testosterone propionate (TP, 100 micrograms/mouse), 17 beta-estradiol (E2, 5 micrograms/mouse) or vehicle for 20 days starting from day 60; daily TP injections (100 micrograms/mouse) for 30 days were started again from day 110 in all the pretreated mice to examine androgen-induced proliferation by incorporation of 5-[125I]iodo-2'-deoxyuridine into the whole seminal vesicles. Both TP and E2 pretreatments significantly increased the seminal vesicle weight found before TP treatment. However, androgen-induced proliferation of the seminal vesicle found in neonatally castrated mice (poor response; long duration with a low peak on day 3) was changed at least in part to that found in mice castrated at adulthood (good response; short duration with a high peak on day 3) only following the TP pretreatment but not at all following the E2 pretreatment. The E2 pretreatment induced poor androgen-induced proliferation with a low peak on day 7.

Age Factors↗
PubMed1988

Introduction and expression of the interleukin 2 receptor (Tac) gene in hematopoietic stem cells with retrovirus vectors.

Retrovirus vectors provide an efficient carrier for introducing a gene into hematopoietic stem cells although expression of the inserted gene is not always successful. We constructed and compared three retrovirus vectors which carried cDNA encoding the light chain (Tac) of the interleukin 2 receptor under the control of different promoters; long terminal repeat (LTR) of murine retroviruses, the early promoter of simian virus 40 (SV40) and the promoter of the class I antigen gene of the major histocompatibility complex. We made three constructs containing these promoters. A first construct did not contain any additional promoter but LTR. A second and a third constructs contained the SV40 and the class I antigen gene promoters, respectively, in addition to LTR. The LTR of retrovirus vectors is derived from MoMuLV except that the U3 region of the 3'LTR of the third construct is derived from myeloproliferative sarcoma virus (MPSV). The second and third constructs were used for infection of bone marrow stem cells as the first construct was less efficient in expression of the interleukin 2 receptor in fibroblasts. Hematopoietic stem cells infected with the recombinant viruses were transplanted into lethally irradiated mice, and the expression of the transduced gene in hematopoietic progenitor cells was analyzed. Analysis of RNA isolated from spleen colonies showed that substantial amounts of interleukin 2 receptor mRNA were made by the construct containing the class I gene promoter and MPSV LTR. However, we could not detect any transcripts from the constructs containing MoMuLV LTR and SV40 early region promoter.

Animals↗
PubMed1988

[Role of gamma-seminoprotein (gamma-SM) and prostatic acid phosphatase (PAP) as tumor markers of prostatic cancer].

Between June, 1986 and December, 1987, the serum gamma-Sm and PAP was measured in 29 men with untreated prostatic cancer, 45 with treated prostatic cancer (32 were well-controlled and 13 poorly controlled), 82 with benign prostatic hypertrophy and 10 with other urological diseases. All of the patients with prostatic cancer had histologically proven disease. Enzyme immunoassay for gamma-Sm and radioimmunoassay for PAP were used. The cut-off value for gamma-Sm was 4 ng/ml and that for PAP was 3 ng/ml. The mean values of gamma-Sm and PAP were statistically high in the untreated group and also in poorly-controlled group. In the untreated group, the rate of positivity for gamma-Sm and for PAP were 69% respectively and 83% of the patients had elevated values for either or both of these markers. In clinical stage A and B, gamma-Sm and PAP values were within the normal limit, however the concentrations of mean gamma-Sm and PAP correlated well with the stage of disease. In the poorly-controlled group, positive gamma-Sm values were detected in 75% and PAP in 67%, whereas almost all of the patients had normal values for these markers in the well-controlled group. In prostatic hypertrophy, elevated gamma-Sm values were detected in 15% and elevated PAP values in 6%. After the onset of treatment, elevated values were normalized in 66.7% of the patients for gamma-Sm and in 68.4% for PAP. In the untreated group, gamma-Sm tended to show a more prompt response. In the ill-controlled group, gamma-Sm and PAP returned to normal in 50% of the patients. gamma-Sm and PAP values were well correlated with the course of the prostatic cancer and the clinical usefulness became more obvious with a combination of these markers.

Acid Phosphatase↗
PubMed1988

Hybrid resistance to parental bone marrow-derived cultured mast cells in the skin but not in the peritoneal cavity of (WB X C57BL/6)F1-W/Wv mice.

When cultured mast cells of (WB X C57BL/6)F1-+/+(WBB6F1-+/+) and WB-+/+(WB) mice were directly injected into the skin of genetically mast cell-deficient WBB6F1-W/Wv mice, mast cell clusters appeared at the injection sites. Although in vitro colony-forming ability is comparable between cultured mast cells of WB mice and those of WBB6F1-+/+ mice, the number of WB mast cells necessary for the appearance of mast cell clusters in the skin of WBB6F1-W/Wv mice was significantly larger than the number of WBB6F1-+/+ mast cells. In spite of the presence of such an apparent hybrid resistance in the skin of WBB6F1-W/Wv mice to mast cells of the WB parent, both WB and WBB6F1-+/+ mast cells grow in the peritoneal cavity of WBB6F1-W/Wv mice with comparable efficiency. This is a demonstration of the tissue-related (nonrecirculating) expression of hybrid resistance against nonmalignant hematopoietic cells.

Animals↗